ArduCopter 2.3 released

Jason is travelling this week, so I'll take the helm for the next software release post.

UPDATE: the motor remapping thing was confusing everyone, so we took that out and returned to the regular motor mapping. That means that APM 2 users with Hexas and Octos should wait for the next version. APM 1 users should be fine with any frame.

NOTE: Hexa and Octo users: there have been motor mapping changes that may affect you. Please don't upgrade until we can update the documentation to reflect the changes. This should happen by the end of the day today (Feb 1).

ArduCopter 2.3 is now available in the Mission Planner. This is the next revision of the ArduCopter 2.2B6 code, which is perhaps the most tested code we've ever released (1288 comments in the thread!) and certainly in my experience the best code, too.

The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P (default is 0.14, so start by turning it down to 0.1. In general tune PIDs in 25% steps).

Now that we've got solid code out there, we can turn to collecting suggested gains for standard frames, and a better guide to how to tune PIDs for your unique setups.

Here are Jason's note on the latest changes (mostly from 2.2B6)

A dampening term called STAB_D has been refined. A D term for all of the Rate based control loops has been added based on Igor's work. Landing for Baro and Sonar has been refined based on JLN's work. A slightly new approach to Loiter and Navigation is being used to try and linearize the pitch and roll for rate control. It tends to use lower gains, yet has a more assertive response in the air.

STAB_D : This is the gyro accretion dampener. This can remove small wobbles during sharp changes in angle commands. Making this too high can have a negative effect in performance and add a memory effect that can cause temporary loss in control. The in flight tuning is ranged so you are just below that effect.

If you haven't noticed before the control loops are in two stages. The first is a PI stage that converts some sort of position or angle error into a desired rate. These generally do not need to be tuned. They are more of a user preference on how fast you want the copter to perform a motion.

The second stage is the actual PID loop that needs to be tuned for the copter. This converts the desired rate into a motor command of some sort. I added a D term based on Igor's recommendation to the PI's for each rate controller. These should show up soon in the mission planner for the release. I cannot give you a concrete answer for how to tune the D terms, because they each depend on their function such as alt hold or loiter, etc.

Still, the absolute most important term is always the Rate_P term for each loop. Start tuning here.

The default PIDs are in the what flies great for a stock jDrones/3DR Quad with the purple motors in X mode.

Note the Mission Planner does not yet highlight these D terms on the main tuning page (it will soon), but you can find them and modify them on in the Parameters list.

Autolanding should now work well (see video above) and the Tri servo issue is now resolved.

The code should now compile with Arduino 1.0 (thank, Randy!), but remember that you need to use the "relaxpatch" version of Arduino in our downloads section.

[Update: we've reverted the below. See update at the top of the post]

Important for Octo users:

We've changed some of the motor orders for some more exotic airframes. We'll be updating the docs on the Wiki in a day or two to reflect this. Pat Hickey explains:

I attempted loiter with the stock PID gains and did not have luck, but I don't blame the software. There are several people who are getting amazing results with 2.4. I just didn't have the time to tune the PID gains. Good luck!

As promised you, I have updated the ArduCopter v2.4 firwmare with my AUTO-LAND mod tested in the 2.2b2xp1. My updated firmware version is now the v2.4xp1 and it can be downloaded HERE with the full PID param files that I have used on my quad.

Of course, I have checked myself on my quadcopter if my mod is working... So, you will find a video of a full test of my firmware with 8 samples of AUTO-LAND real tests...

For explorers and beta testers which are interested to explore in deep and improve freely the features of the fascinating ArduCopter you are welcome in my blog HERE...

I don't see the option for the LV EZ4 in the dropdown list of sonar devices on the configuration screen. Do I Use LV EZ0 option? Is there another way to configure the LV EZ4? I'll be installing in on 3DR Quad w/APM1 running 2.5.5.